The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 1978
Filed:
May. 06, 1976
David Smith Horne, Warrington, EN;
Robert Eric Talbot, Burtonwood, EN;
Peter John Russell, St. Helens, EN;
Interox Chemicals Limited, London, EN;
Abstract
The present invention provides a process for making diphthaloyl peroxide by reacting phthalic anhydride with aqueous hydrogen peroxide at a pH controlled to between pH 8 and 10, preferably pH 8.8 to 9.2 and a low temperature preferably maintained at 0.degree. to 5.degree. C, and thereafter removing diphthaloyl peroxide from solution, suitably by acidification and filtration. Preferably excess solid phthalic anhydride is employed and is filtered out before the solution is acidified. Desirably the concentration of active oxygen species is maintained at below 0.3 moles/liter. Diphthaloyl peroxide is particularly suitable for bleaching/washing fabrics, optionally in conjunction with an inorganic persalt e.g. sodium perborate, at a temperature of from 30.degree. to 60.degree. C.